Checking if an object is a given type in Swift

Question

I have an array that is made up of AnyObject. I want to iterate over it, and find all elements that are array instances.

How can I check if an object is of a given type in Swift?

Answer 1

If you want to check against a specific type you can do the following:

if let stringArray = obj as? [String] {     // obj is a string array. Do something with stringArray } else {     // obj is not a string array } 

You can use "as!" and that will throw a runtime error if obj is not of type [String]

let stringArray = obj as! [String] 

You can also check one element at a time:

let items : [Any] = ["Hello", "World"] for obj in items {    if let str = obj as? String {       // obj is a String. Do something with str    }    else {       // obj is not a String    } }